Kaiyo Japanese Mizunara Oak Cask Strength WhiskyKaiy whisky is matured in the finest Japanese Mizunara oak casks. These casks are handmade due to Mizunara oaks delicate wood grain. They are among the rarest casks in the world and are considered the finest in which to mature whisky. After years of maturing our casks go on a final maturation at sea voyage for up to 3 months, leaving from Osaka Japan. What makes mizunara oak distinct from European oak and White oak? For one, it enjoys a unique sweet